Critical Review of Using the Video in Teaching Essay

Critical Review of Using the Video in Teaching - Essay Example The use of Audio-visual aids started long ago with ancient educationists. Desiderius Erasmus (1466-1536) advocated for the use of pictures and other visuals instead of memorization as a technique of learning. John Amos Comenius (1592-1670), in his orbis sensulium pictus, started the use of illustration in textbooks. His books contained one hundred and fifty pictures on aspects of everyday life. Jean Jacques Rousseau (1712-1778) and other educators emphasized the use of pictures, illustrations and other playthings. During the beginning of the 20th century, Nelson I. Greene coined the term visual education. Eric Ashby (1967) categorized the revolutions in education. He listed the use of electronic media as the fourth revolution. Cobun (1968) discovered that people learn 83 percent of knowledge through sight. Through his research, he also discovered that people remember 50 percent of what they hear and see and only 10 percent of what they read. This, among other discoveries, underscored the need for the use of audio-visual aids. They help the teacher clarify concepts, and make learning more interesting, appealing and vivid. These aids also provide considerable advantage in information learning, imagination, retention and cognitive ability level. Principles that are hard to understand usually become easy with skilled use of Audio-visual aids. Raymond Wyman (1957) observed that excessive use of words in teaching and learning results to verbalism and forgetting (Sampath 2008, Pp. 80-82). Sampath argues that, in the teaching- learning process, media augment a variety of other teaching materials and techniques (Sampath 2008, Pp. 80-82). He also observed that creativity is important in coming up with ways of combining media and other materials and techniques. Though visual aids have numerous advantages, they also have limitations. For example, a photograph can distort the real thing. The effectiveness of a video as a teaching aid will depend upon the angle of filming, t he recorder used, and the writing provided (Das 2007, 163). There is also the risk of technical problems. Regardless of the quality of a machine, there is always the risk that it can break down. Projectors can break down; DVDs can get damages among other misfortunes. There is also the possibility of distracting the students from the focus in a picture or a video. These materials are also resource, time and space intensive. Nevertheless, the use of visual aids is the future of instruction. Riel (2000) argues that personal learning will change, and there will be more collaboration (Watson & Downes 2005, Pp. 9-24). Therefore, there is a need for more research to improve the efficiency of modern instructional techniques and to invent new ones. It is also of immense importance to review existing knowledge in view of either authenticating it or identifying its redundancy. Video as a collaborative tool Herder, Subrahmanian, Talukdar, Turk, and Westerberg (2002) conducted an experiment to f ind out how they could teach a course in Delft University of Technology (TUD) and Carnegie Mellon University (CMU) at the same time. The two universities’ locations were different geographically. They formed teams constituted students from both countries. Their aim was for students to interact with different people from a different culture. The students communicated through a variety of means. They recorded lectures from

Chemistry Practical Assignment - Copper carbonate Lab Report

Chemistry Practical Assignment - Copper carbonate - Lab Report Example Take the given CuCO3 and weigh around 0.2 gm to the nearest to 0.01 gm of it in a test tube. Carefully tight the cork fitted with a delivery tube on the mouth of the test tube and use sealant to close the leakage if any in the tube. Filled a water tray and fill the graduated cylinder with water, cover it and gently invert the graduated cylinder and bring it down so that its mouth of it is just beneath the water level in the filled tray. Ensure that there is no air bubbles at the time of putting graduated cylinder and it is fixed with the help of clamp. Put the delivery tube inside the mouth of the cylinder so that the air is passed to the inverted graduated cylinder. The experimental setup should look like as shown in figure-1 (Decomposition of copper carbonate, n.d.) and by putting the sealant material minimize the leakage from the corners and through the cork. Now heat the copper carbonate gently with a burner (Thermal decomposition, 2007). The gas so formed is passed to the inverted graduated cylinder (Decomposition of copper carbonate a, n.d.). As soon the formation of gas bubbles stops, immediately take out the burner and keep the graduated cylinder perpendicular and take the meniscus reading and find out the volume of water displaced by the gas. Record the temperature of water and barometric pressure in the laboratory. Repeat the experiment at least thrice and record the weight of copper carbonate taken for all the experiments and corresponding gas volumes. Safety and Precautions: An irresponsible act can threaten our own safety and health in the laboratory (On carrying out experiment in the laboratory, n.d.) and therefore before conducting the experiment wear safety goggles and lab apron (Safety and Laboratory Rules, 1999). Avoid ingesting chemicals and use caution around open flames (Decomposition of copper carbonate, n.d.) Calculations and Discussions: For evaluating both the equations, the mole concept is used (mole concept & Mole concept and mole conversion, nd). First using the following gas law the volume of gas at NTP has to be find out (Physical laws & Scaling, 2003). P1 V1 P2V2 ---- = ------- ----- (1) T1 T2 As we have already collected the P1 (barometric pressure), V1( the gas volume ), T1 (the water temperature) and P2 is 760 mm of Hg and T2 is 273K and putting all values in above equation we will get, V2 the volume of gas at NTP. Now according to equation 1, 2CuCO3(s) ----- Cu2O(s) + 2 CO2 (g) + O2 (g) We will get 2 moles of carbon dioxide and 1/2 mole of oxygen from 2 mole of copper carbonate. Now the molecular weight of CuCO3 = 123.5 The Weight of copper carbonate taken for study = 0.2 gm. Therefore the mole of copper ca